Mammal. Scottish Highland sheep are a hardy breed, with thick, shaggy coats that enable them to survive extremely harsh weather. They can tolerate cold and snow, and thrive in bleak, rugged environments where other breeds would perish. In summer, their long lashes and forelocks shield their eyes from flying insects. The female sheep, called ewes, have strong maternal instincts and guard their lambs. They usually give birth to twins, or sometimes triplets. The modern Scottish Highland breed is descended from sheep who were raised by monks in the Twelfth Century.